Physiological measures in participants with chronic fatigue syndrome, multiple sclerosis and healthy controls following repeated exercise: a pilot study

Clin Physiol Funct Imaging. 2018 Jul;38(4):639-644. doi: 10.1111/cpf.12460. Epub 2017 Aug 7.


Purpose: To compare physiological responses of chronic fatigue syndrome (CFS/ME), multiple sclerosis (MS) and healthy controls (HC) following a 24-h repeated exercise test.

Methods: Ten CFS, seven MS and 17 age- and gender-matched healthy controls (10, CFS HC; and seven, MS HC) were recruited. Each participant completed a maximal incremental cycle exercise test on day 1 and again 24 h later. Heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), oxygen consumption (V˙O2), carbon dioxide production and workload (WL) were recorded. Data analysis investigated these responses at anaerobic threshold (AT) and peak work rate (PWR).

Results: On day 2, both CFS and MS had significantly reduced max workload compared to HC. On day 2, significant differences were apparent in WL between CFS and CFS HC (93 ± 37 W, 132 ± 42 W, P<0·042). CFS workload decreased on day 2, alongside a decrease in HR but with an increase in V˙O2 (ml kg min-1 ). This was in comparison with an increase in WL, HR and V˙O2 for CFS HC. MS demonstrated a decreased WL compared to MS HC on both days of the study (D1 81 ± 30 W, 116 ±30 W; D2 84 ± 29 W, 118 ± 36 W); however, patients with MS were able to achieve a higher WL on day 2 alongside MS HC.

Conclusion: These results suggest that exercise exhibits a different physiological response in MS and CFS/ME, demonstrating repeated cardiovascular exercise testing as a valid measure for differentiating between fatigue conditions.

Keywords: cardiovascular exercise testing; fatigue; postexertional malaise.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Anaerobic Threshold
  • Bicycling
  • Blood Pressure
  • Case-Control Studies
  • Diagnosis, Differential
  • Exercise Test*
  • Exercise*
  • Fatigue Syndrome, Chronic / diagnosis*
  • Fatigue Syndrome, Chronic / physiopathology
  • Fatigue Syndrome, Chronic / psychology
  • Female
  • Heart Rate
  • Hemodynamics*
  • Humans
  • Male
  • Middle Aged
  • Multiple Sclerosis / diagnosis*
  • Multiple Sclerosis / physiopathology
  • Multiple Sclerosis / psychology
  • Oxygen Consumption*
  • Perception*
  • Physical Exertion*
  • Pilot Projects
  • Predictive Value of Tests
  • Time Factors
  • Young Adult